1. Field of the Invention
The present invention relates to solid electrolytic capacitors and a method of manufacturing same.
2. Description of Related Art
As shown in FIG. 12, a conventional solid electrolytic capacitor comprises a capacitor element 101 from which an anode lead 112 projects forward and having a surface on which a cathode layer 115 is formed, an exterior resin 102 covering the capacitor element 101, and an anode terminal 103 and a cathode terminal 104 including, respectively, an anode terminal surface 103a and a cathode terminal surface 104a which are exposed from a bottom surface 102a of the exterior resin 102. To a top surface of the anode terminal 103, connected is a connecting member 105 having a predetermined height. Also, to a top end of the connecting member 105, connected is a tip end part 112a of the abode lead 112. To the cathode terminal 104, connected is the cathode layer 115 of the capacitor element 101.
Thus, by connecting the tip end part 112a of the anode lead 112 to the anode terminal 103 by means of the connecting member 105, it is possible to arrange the anode lead 112 at a predetermined position in the height direction.
In the solid electrolytic capacitor described above, however, welding, which is one of factors which reduce productivity of solid electrolytic capacitors, is necessary in both a step of connecting the connecting member 105 to the anode terminal 103 and a step of connecting the tip end part 112a of the anode lead 112 to the connecting member 105.
In view of the above problem, in order to reduce the number of welding operations, there has been proposed a method in which, by performing a bending process on one metal plate, formed is an anode terminal which includes the conventional anode terminal 103 and connecting member 105 integrally.
In particular, as shown in FIGS. 13a to 13c, there has been proposed a method in which, the anode terminal is formed by performing the bending process on a flat plate-like anode frame member 106. As shown in FIG. 13a, the anode frame member 106 comprises a terminal forming part 161 including a bottom surface 161a which is to be the anode terminal surface 103a, a projection part 162 formed at a side edge of the terminal forming part 161, and a belt part 163 extending in a belt shape from the projection part 162 along the side edge of the terminal forming part 161. As shown in FIG. 13b, the belt part 163 is bent upward vertically to the projection part 162, and as shown in FIG. 13c, the projection part 162 is bent vertically to the terminal forming part 161 so that the belt part 163 is arranged vertically to a top surface of the terminal forming part 161 to form the anode terminal.
To a top end 163a of the belt part 163 included in the anode terminal, connected is the tip end part 112a of the anode lead 112 of the capacitor element 101.
When forming the anode terminal by performing the bending process on one metal plate in such a manner, there is no need for welding between the anode terminal 103 and the connecting member 105, which is necessary in a conventional way, and therefore, the productivity of the solid electrolytic capacitor increases.
However, if an error (deviation from 90 degrees) occurs in a bending angle when bending the belt part 163 vertically to the projection part 162 (FIG. 13b), it is possible that the position of the belt part 163 deviates forward or backward from a position where the tip end part 112a of the anode lead 112 is to be connected to the belt part 163, resulting in a poor connection between the belt part 163 and the tip end part 112a of the anode lead 112. Specifically, in a solid electrolytic capacitor having a large width, there will be a considerable deviation of the belt part 163 caused by the error in the bending angle.
Also, in the case where the belt part 163 and the tip end part 112a of the anode lead 112 are connected to each other by resistance welding, the tip end part 112a of the anode lead 112 is pressed to the top end 163a of the belt part 163, and therefore, a great power is applied to the belt part 163 downward. However, since a bottom end of the belt part 163 is not directly coupled to the terminal forming part 161 located vertically to the belt part 163, the belt part 163 lacks strength to withstand the power applied in the resistance welding operation, and therefore, it is possible that the belt part 163 is bent by said power.